Several attempts have been made in the prior art to restrict usage of a power tool, e.g., a battery-operated, hand-held power tool, only to authorized users. The goal is to at least deter, if not prevent, the theft of the power tools and/or the battery packs associated with the power tools.
For example, the following proposals for solving this problem have been disclosed.
In US 2008/0238609 A1, a battery-operated electric hand tool device comprises control electronics, a wirelessly and contactlessly responding transceiver, and a storage unit in which an authorization code is stored. A locked mode of operation is distinguishable from a released mode of operation. In order to improve theft protection, a wire-bound or wireless interface is provided from the control electronics of the electric hand tool device to a battery pack such that locking data can be transmitted from the control electronics of the electric hand tool device to the battery pack, can be stored in a storage device of the battery pack, and can then be read out of the storage device again.
Similarly, in U.S. Pat. No. 6,872,121, an electrical hand tool device comprises control electronics and a transmitter and receiver, which operates in a wireless and contact-free manner, and a storage medium in which an authorization code is stored. An operation locking state can be differentiated from an operation release state. An external transmitter and receiver means is accommodated in a separate portable device. Communication with the transmitter and receiver means of the electrical hand tool device can be produced in a defined fashion by actuating the external transmitter and receiver means to change the operation state of the electrical hand tool. Communication is provided only to change the operation state and optionally to change the authorization code.
In JP 2004-181549 A, an electric tool has a mode changing means for switching between an ordinary operation mode and a tool unusable mode that prevents usage of the tool. An identification code storage means stores an identification code that is specific to the tool. An identification code input means is adapted to input the identification code. A control means is connected with these means and controls operation of the electric tool. When the control means determines that the identification code inputted via the identification input means coincides with the identification code stored in the identification code storage means, it changes the tool operational state from the tool unusable mode to the ordinary operation mode. When the inputted identification code is different from the stored identification code, use of the electric tool is prevented.
However, these known proposals suffer from one or more problems.